1. Field of the Invention
The present invention relates to a method used to zoom in selective plot area in display, and more particularly to the method capably used in plotting calculator to zoom in any plot area selected in display.
2. Description of Related Art
The general plotting calculator sold in market, such as CASIO's product, must firstly remove an optical point displayed in display screen onto a starting point of an area going to be zoomed in when proceeding to zoom in partial area of plot shown in display of a plotting calculator, then to key in the enter key to confirm the input data, and secondly further remove the optical point, at this moment a rectangle box shown, to a terminate point in where a rectangle area shown the partial area of plot to be zoomed in is built, therefore, the selectively area of plot will be then zoomed in and shown a more clear plot after the enter key is keyed in again to execute the zoomed in plot operation.
But according to the method mentioned above, resulted from using visual operation to approximatively position that starting point and terminate point of rectangle box as a zoomed in area, the way how to precisely choose the starting point and terminate point of a zoomed in area to be selectively shown is become a serious problem to user. User must repeat the selective operation to zoom in plot again if the area already zoomed in is just not the area going to be zoomed in to user's want. Therefore, it is unsatisfactory to general user and more inconvenient to people who is unfamiliar the function to zoom in selective plot in general plotting calculator.